Now teenage thugs can blame their hormones for bad behaviour

Teenage thugs could be suffering from a mental illness caused by a hormonal imbalance, scientists suggest today.

A Cambridge University study of boys aged between 14 and 18 found a link between levels of stress hormone cortisol and anti-social behaviour.

Cortisol is produced in higher amounts at times of stress and is thought to cause more cautious behaviour, helping people to keep a lid on their temper and any violent impulses.

Delinquents revealed: Scientists say teenage thugs could be suffering from a mental illness caused by hormones

But in delinquent youths levels of the hormone tend not to rise when they are put in a high pressure or aggressive environment, the 18-month study found.

Its findings point to the possibility of drugs being used in the future to control teenagers’ behaviour.

And, at least in some cases, the study also offers an alternative to the theory that teenage bad behaviour is fuelled by peer pressure and a desire to fit in.

Scientists at Cambridge’s child and adolescent psychiatry department recruited 165 boys from schools, pupil referring units and the youth offending service.

Saliva samples were taken and tested for cortisol and they were asked to play a computer game, which unknown to them, had been rigged.

As they played, critical messages from an unseen opponent-were flashed up on the screen. Researcher Dr Graeme Fairchild said: ‘The game was rigged to be impossible. The whole point is to make them feel angry and annoyed, and as if they were being socially evaluated.’

Saliva samples were taken again afterwards and amounts of cortisol compared. As expected, levels of the hormone – which ‘glues’ memories into the brain – rose under stress in the boys without behavioural problems.

But they tended to fall in the unruly youngsters, the journal Biological Psychiatry reports.

The study, funded by the Wellcome Trust, suggests anti-social behaviour may be more biologically based than previously thought and that drugs could be developed to tackle it.

Filed in: World News